House Republican leaders expressed confidence Wednesday that the Ryan budget blueprint will pass, despite grumbling from some in the conference that the document does not go far enough to curb spending and change social programs.

“It’ll pass,” GOP Whip Kevin O. McCarthy, R-Calif., told reporters one day after House Budget Committee Chairman Paul D. Ryan unveiled the 10-year roadmap. Ryan himself was assured as well, telling reporters a day earlier that he been speaking to colleagues for months and expects the budget to be adopted.

Ten Republican House members voted against Ryan’s budget blueprint last year, and the challenge leadership faces is ensuring more members do not jump ship. That is more difficult this year because an election is on the horizon and because the budget follows a bipartisan spending agreement that 62 House Republicans voted against. Only 17 Republicans would have to vote against the measure to sink it, assuming that as last year, no Democrats support it.

Already, Reps. Tim Huelskamp of Kansas, Raul Labrador of Idaho and Matt Salmon of Arizona, all of whom voted for last year’s budget, said they are rethinking their support, staying undecided because the plan calls for spending of $1.014 trillion in fiscal year 2015, which is higher than they like.

Labrador added that although the budget is loaded with conservative priorities, he has little faith that leaders will try to implement any of them.

“There’s also a lack of commitment from the party, from the Republican members of Congress, to actually doing what the Ryan budget says,” he said. “I came here to actually get things done, not just vote on a document that is just for show.”

Rep. Mick Mulvaney, R-S.C., said he too is undecided, in part because of a vote to stem Medicare pay cuts to doctors last week. Ryan’s budget includes a permanent “doc fix,” but Mulvaney said he wants to make sure it is paid for satisfactorily, rather than with what he sees as gimmicky offsets, like those attached to a short-term extension that passed the House by voice vote last week.

“It’s raising a new issue to look at,” he said. “We can’t continue to do stuff and not think it’s going to have an impact.”

Speaker John A. Boehner of Ohio responded to conservative criticism Wednesday morning, when asked whether any budget could satisfy far-right groups like the Tea Party Patriots, who have panned Ryan’s plan.

“No. No,” he answered. “If we want to make perfect the enemy of the good every day, we’d never get anything done.”

Boehner acknowledged that the conference faces some problems in trying to pass the budget, but he said the Ryan plan is not much different from previous years’ budgets, which have passed fairly easily.

“This is essentially the same budget we’ve put forward the last four years,” Boehner noted. “It’s laying out our vision. Solving the problems that address America.”

And there is some bright spots for leadership. Rep. Jim Jordan, R-Ohio, for instance, said he will be voting for the budget even though he voted against the spending deal Ryan struck with Senate Budget Committee Chairwoman Patty Murray, D-Wash.

“I didn’t like the number, voted against it in December. But this is about the policy ideas. The number’s already set. That’s … water under the bridge,” he said.

Still, how Ryan deals with Medicare could become an issue as well, particularly for members seeking higher office. The plan maintains $716 billion in Medicare cuts instituted to pay for the Affordable Care Act.

“That gives me a little heartburn,” said Rep. Phil Gingrey, who voted against Ryan’s last budget. “My pledge to the people of Georgia is that I wouldn’t vote for any budget that has spending going forward for Obamacare.”

Ryan, however, painted an out into the budget on that issue if candidates choose to take it. The Medicare funding is set aside in a reserve fund that can then be used to “shore up” Medicare, according to the Budget Committee.

When asked, Rep. Bill Cassidy, R-La., who is running to unseat Democratic Sen. Mary Landrieu in a very close race, used that policy to inoculate himself against criticism from the left that he is voting to slash Medicare.

“What Sen. Landrieu voted on … took it out of Medicare and put it into the new entitlement called Obamacare. The Ryan budget takes that back and puts it into Medicare,” he said.

Finally, the fact that the Ryan budget bumps defense spending at the expense of discretionary spending over the next ten years is chasing away some GOP votes. Rep. Walter Jones of North Carolina said he will vote against the budget for that reason and Rep. Justin Amash of Michigan said he is undecided but thinks the military spending number is too high.